Or in other words if you're used to seeing switches from the electronics side of the world: 2 way: SPST 3 way: SPDT 4 way: DPDT I once lived in a house with

Or in other words if you're used to seeing switches from the electronics side of the world: 2 way: SPST 3 way: SPDT 4 way: DPDT I once lived in a house with a 5(!) gang box with three of the switches wired to the upstairs hall light incorrectly and another switch upstairs. It was as big a mess as you'd imagine.